sputtering

I know that I am due for a valve adustment on my type 2 VW engine, but I was curious as to what is causing my recent problem. All of a sudden my engine is starting to sputter at cruising speed, regardless of the gear that I am in. When I accelerate hard, everthing is fine, but when I cruise at a constant cruising speed (55mph in 4th gear for example), start to get an excessive amount of backfiring and reduction in power. Kind of like when you start to run out of gas. Is this a sign of valves out of adjustment, carburation problems, bad plugs/wires?

could be a few things like clogged carb idle jet(s). what carbs do you have?

dual webers

Stay tuned since many of us are having that problem, my solution my not work for you, since Mike has already explained there could be a whole bunch of reasons for it, but I'll report as soon as the problem in my Spyder has been fixed.

have your points closed up?
mine was popping back and I set the points and now its OK

sounds good karl. I will wait to see what you find out. In the meantime, I will post my results as well... the plugs and wires, valves out of ajustment, dirty carbs, etc.

check timing, valve adjustment, blocked idle jets, exhaust and intake leaks. If it is popping at idle, then it could be an indication of lean running through one or more barrels typically caused by : blocked idle jets, exhaust and intake leaks. Make sure your timing and valves are correct to rule those out first.

Have fun!
Mike

This is probably a whole different topic, but, when I go to my local mechanic who feels confident that he can work on this relic, is there anything I should be concerned about? I am sure most mechanics look at an air cooled VW and think it is quite simple. Are there certain tools that are unusual and not normally available in most modern day shops?

Unless he's doing a major engine or transaxle overhaul, the tools required are pretty simple. He will need a tool to balance the carb's, aside from that, metric wrenches, feeler gauge and a timing light are all that's """usually""""" needed.

if all else fails do a compression check

beware of the mechanics that say they know what they are doing on these things....does he work on sandrails or modified VWs for a living? If you don't see any other engines like yours in his shop, think about it.

I was soaked by a "knowledgeable" VW guy...it made me learn how to do it on my own.

Let us know what you find out.

Mike

damn computer -

I know what it is. Worn hex bar shaft. Yessir. Check that first. You can balance the carbs at idle, and it will run fine -- on the idle stops. But as soon as pull on the throttle a worn hex bar shaft will crank the carbs totally out of balance. And the worst place will be at the top range of the idle circuit (before the mains come in), which should be cruising at 55 in 4th.

When you tromp the throttle, the carbs go to wide open, the accelerator jets pump extra fuel and the carbs are relatively more in balance than when just cracked on the idle circuits. So it seems like the problem isn't there when you tromp the throttle. But it is still there, just not as noticable.

Actually, I really don't know for sure what your problem is. But that's my guess.

Also, Barry (goofycat) showed me how -- if one of the hex bar lever arm set screws get loose and the lever arm slides on the hex bar -- that will suddenly mess things up too.

Mark

I just corrected a similar problem with Karl Dempwolf's engine. His problem was not so much a worn hex bar but mis-alignment of the pivot screws. The adjusting arms from the hex bar to the carbs was also affected due to the mis-alignment. This caused the carb on the 3-4 side to open off of idle before the carb on the 1-2 side. The difference in the opening was approximately 3/8". That's significant and when he was driving the car at the split between idle jets and main jets, the car would hesitate, stutter, sputter, fart and just plain not run well.

All of that is now fixed and he's a happy camper.

BTW, I spent an inordinate amount of time centering the hex bar, adjusting the throttle heim joing arms and balancing the carbs to ensure that all 4 barrels were drawing air correctly and that the air mixture screws were at their optimum settings.

LJ--you are the man. I wish I lived close to you. v

So I shouldn't have use my hex bar in place of my racing jack handle?
Opps!

UPDATE..... So far so bad. My car spent Friday afternoon with my "local" mechanic. It looked like the problems was going to be dirty carbs. When he got it all back together, I took it for a test ride and found the car to run 10X worse. Completely out of tune. I don't think he really knows how to properly adjust a weber carb. I'll see how monday goes.

Vicki, Me too!!!!

Chad, read my post above. Make sure the mechanic grabs the main throttle leverage arm when he tests for carb throttle plate opening.

In other words, the leverage bar that attaches to your main throttle cable. If he uses either of the arms that are attached to the carbs, it won't give him a true picture of the carbs syncronization. Also, once that is adjusted propery (both carbs open exactly the same) then he needs to make sure that the swivel balls located on your air cleaner base plates are adjusted properly. If they are not, the hex bar will move up and down during acceleration.

When all of that is done, he needs to balance both carbs. (make sure that both are drawing the same amount of air) He then may need to re-adjust the heim joing linkage between the hex bar and the carbs.

Then----- repeat the whole process. Finally, he needs to turn the mixture screw in, until it stops. Then rotate the screw out until the engine gains speed. If he goes too far, the engine will lose speed so, he needs to find that "sweet" spot.

Oh, when he finishes that, he needs to go back and check everything else as mentioned above.

BTW, do you live in So. Cal???? If so, I can do the adjustments or if you're so inclined, you can send a private jet and I'll travel to yourlocation LOL

I will bring this response with me on Monday morning. I hope it helps. BTW, I am in Minnesota.

If you order up the private jet, I'd be happy to visit Minnesota LOL

chad
Please let me know if you have success and which garage you took it to. Courtney's just west of 494 off 62 is where I went with an oil cooler issue.
thanks,
keith

IN CONCLUSION to this post....

My car runs better now than I can ever remember. Before my recent sputtering problem, I would get the occasional POP when letting off the gas. It is now POP free. I just don't know exactly what the problem was. Perhaps it was a combination of the following: The valves were adjusted, one was off pretty bad, the points were readjusted and the timing was set, carbs were removed, cleaned, reinstalled, adjusted and synchronized. Adjusting the carbs took longer than expected as my "local mechanic" had to talk to someone at Weber to get the correct adjustment procedures. Total bill...$237.78. Shop rate is $50/hour. Keith Jones... I live two hours west of the metro, probably not the place to get future service done on your spyder. Thanks to all for your help!!!

This winter when I was having some of the same problems you've had, my mechanic also ended up calling Weber directly and got the carbs fixed correctly after talking with them and having them guide him with the settings. I think they had him change the jet size too (??). I can never remember details. v